Nephrotic syndrome massive proteinuria Why?

Blood in the water and its solutes through renal glomerular filtration into a small capsule of urine, The wall must go through capillary endothelial cells, epithelial cells and the basement membrane, this three-tier structure called the glomerular filtration membrane. The three tiers are certain filtration membrane pores, allowing only a certain molecular weight and molecular diameter through the material and thus constitute a barrier filtration membrane pore size, the three-tier structure of the surface are lining sialoprotein, within the glomerular basement membrane , osteoporosis, type of heparin sulfate-rich, these substances in the human body fluid environment with negative charge, the exclusion of the solutes through negative charge, which constitutes a charge membrane filtration barriers. Meanwhile, in between the ball glomerular mesangial within the glomerular filtration barrier for a regulatory role, the result of glomerular filtration also play a certain impact. Under normal circumstances, the vast majority of blood. The protein can not pass glomerular filtration barrier, especially macromolecules with a negative charge and the almost entirely through albumin, a small amount through the small molecular filtration membrane protein can be in the tubular reabsorption. . Thus, although every day about 10 to 15 kg flows through renal plasma protein cycle. However, the discharge of urine protein less than 150 mg. In the nephrotic syndrome, caused by a variety of pathological factors, the role of the barrier filtration membrane destruction, such as pore size larger or negative charge reduced, resulting in a large number of protein leakage, and far more than the tubular reabsorption capacity , so a large number of proteinuria.